Valiant to Duster disc brake/rear brake swap

Good morning everyone, im sure this has been discussed 1,000 times but using the search feature I was still having a hard time getting a definitive answer, or maybe just getting it through my thick skull.

I have a '74 Gold Duster with the slant six and SBP manual drums all around. 10" front - 9" rear.

I am acquiring a '73/'74 Valiant 4-door BBP, power disc, 318, unsure on which diff yet (don't have it home)

I would like to convert the Duster to Big bolt pattern and also Disc in the front utilizing parts from the Valiant. From my understanding they are mostly interchangeable brake/suspension wise. My questions are:

1. If I pull the entire disc brake spindles from the valiant, will they be a direct swap to the Duster? Or will I have to change control arms, tie rods, ball joints, etc.

2. The Duster, although drum all around, has a manual disc master cylinder on it. I would like to keep the manual brakes for right now, because id rather not mess with rebuilding or replacing the crusty looking booster. Can I swap to the disc in front, but keep my non-power disc master set up? Will I need a proportioning valve, either aftermarket adjustable or do I need to use the original metering block from the valiant?

3. I don't have the valiant home yet, but will a 7 1/4 BBP (assuming) rear end from the valiant be a direct swap to the Duster?

Down the line I would like to pull the 318 and get the V8 K-member out from under the valiant, and swap the rear end as well. But for right now my plan is to take it one step at a time, and focus on the front disc conversion. I appreciate all of the information you guys are willing to give! In the meantime I am going to do some more reading...